Trichoderma and its secondary metabolites improve yield and quality of grapes

Trichoderma is one of the most studied and applied fungal biocontrol agents. The benefits of these microorganisms to the plant include: suppression of pathogens, growth promotion, enhanced nutrient availability and induction of resistance. The biological activity is related to the variety of metabolites that they produce. These metabolites have been found to directly inhibit the pathogens, increase disease resistance and enhance plant growth. In this study, we have examined the effect of two Trichoderma strains and their secondary metabolites on Vitis vinifera in terms of induction of disease resistance, plant growth promotion and increase of polyphenols or antioxidant activity in the grapes. Applications of T. harzianum M10 or T. atroviride P1, as well as their respective major secondary metabolites, harzianic acid (HA) and 6-pentyl-a-pyrone (6PP), have been conducted in greenhouse by foliar spray or drenching. The treatments suppressed the development of powdery mildew caused by Uncinula necator. In a field experiment, a spore suspension of T. harzianum strain T22 or a 6PP solution was applied until fruit harvest. The results indicated that both T. harzianum T22 and 6PP are able to improve crop yield and increase the total amount of polyphenols and antioxidant activity in the grapes. The effects of the isolated natural compounds were comparable with those obtained by using the living fungus

Trichoderma-based products and their widespread use in agriculture

Governing bodies throughout the world, particularly in Europe, are now implementing legislative mandates with the objective of decreasing dependence on pesticides in agriculture to increase consumer and environmental safety. In order to reduce the risks associated with pesticide applications and reduce dependency on their use, Directives will promote low pesticide-input by implementing integrated pest management (IPM), and provide the means to establish the necessary conditions and measures to employ these practices, as well as to ensure security of commercial products. One approach includes the use of biological control agents and their products as alternatives to synthetic agro-chemicals. Trichoderma spp. are widely studied fungi and are among the most commonly used microbial biological control agents (MBCAs) in agriculture. They are presently marketed as bio-pesticides, biofertilizers, growth enhancers and stimulants of natural resistance. The efficacy of this fungus can be attributed to their ability to protect plants, enhance vegetative growth and contain pathogen populations under numerous agricultural conditions, as well as to act as soil amendments/inoculants for improvement of nutrient ability, decomposition and biodegradation. The living fungal spores (active substance) are incorporated in various formulations, both traditional and innovative, for applications as foliar sprays, pre-planting applications to seed or propagation material, post-pruning treatments, incorporation in the soil during seeding or transplant, watering by irrigation or applied as a root drench or dip. Trichoderma-based preparations are marketed worldwide and used for crop protection of various plant pathogens or increase the plant growth and productivity in diverse cultivated environments such as fields, greenhouses, nurseries; in the production of a variety of horticultural, fruits, trees and ornamental crops. A survey was conducted of Trichoderma-containing products found on the international market to obtain an overall perspective of the: 1) geographical distribution, 2) product composition and identity of Trichoderma species selected, 3) contents combined with Trichoderma in the products - other microbial species or substances in the mix, 4) number of products available globally and geographically, 5) number of products registered or having use specifications, 6) product formulations and applications, 7) manufacturer claims - target use, target pests, product type and effects of applications. The largest distribution of Trichoderma bioproducts is found in Asia, succeeded by Europe, South- Central America and North America. The majority of the labels indicated fungicidal properties, but only 38% of the marketed merchandise are registered. Ten Trichoderma species are specifically indicated, but many labels indicate a generic Trichoderma sp. or spp. mix in the list of ingredients. The most common formulation is a wettable powder, followed by granules. Generally, Trichoderma are applied to the seed or propagation material at the time of planting, then the secondary use is during plant development. On the whole, the target use is for the control of soilborne fungal pathogens such as Rhizoctonia, Pythium and Sclerotinia, and a few foliar pathogens such as Botrytis and Alternaria; whereas the minor use indication is for plant growth promotion. The use of Trichoderma-based biological products will have an important role in agricultural production of the future, in light of changing worldwide perspectives by consumers and governing bodies

Secondary metabolites from the endophytic fungus Talaromyces pinophilus

Endophytic fungi have a great influence on plant health and growth, and are an important source of bioactive natural compounds. Organic extracts obtained from the culture filtrate of an endophytic strain of Talaromyces pinophilus isolated from strawberry tree (Arbutus unedo) were studied. Metabolomic analysis revealed the presence of three bioactive metabolites, the siderophore ferrirubin, the platelet-aggregation inhibitor herquline B and the antibiotic 3-O-methylfunicone. The latter was the major metabolite produced by this strain and displayed toxic effects against the pea aphid Acyrthosiphon pisum (Homoptera Aphidiidae). This toxicity represents an additional indication that the widespread endophytic occurrence of T. pinophilus may be related to a possible role in defensive mutualism. Moreover, the toxic activity on aphids could promote further study on 3-O-methylfunicone, or its derivatives, as an alternative to synthetic chemicals in agriculture

ACTIVITY OF CHESTNUT TANNINS AGAINST THE SOUTHERNROOT-KNOT NEMATODE MELOIDOGYNE INCOGNITA

Studies on the effects of tannins on plant-parasitic nematodes are few. A new formulation of a hydrolysable tanninextracted from chestnut (SaviotaN®) was tested for efficacy in controlling Meloidogyne incognita. Therefore, in vitro andpot experiments on tomato were performed to investigate the nematicidal activity of tannin aqueous solutions at differentconcentrations on M. incognita. In the in vitro experiment the following concentrations of tannin at 0.30, 0.40, 0.50, 0.75,1.00, 1.25, 1.50 g L−1 were tested for their effect on the nematode. The second-stage juveniles (J2s) immobility increasedwith increasing concentration and exposure time. All tested tannin concentrations were effective to reduce viability fromabout 45 to 70% after 10 days of exposure, in comparison to the treated and untreated controls. The immobile J2s recoveredtheir mobility over time after rinsing and transferring them in water, showing a nematostatic activity of tannins. In the potexperiment, tannins, as aqueous solutions at rates from 0.30 to 1.50 g L−1, were applied to soil at three different applicationtimes (1: only at transplant; 2: at transplant, two weeks after transplant and repeated every seven days; 3: at transplant andtwo weeks later). The activity of tannins was compared to treated and untreated controls. Tested rates mostly repeated wereeffective to control nematode attack in comparison to untreated control. The height of treated plants was not significantlyinfluenced by the different applied rates of tannins, whereas nematode population density and root galling index wereaffected by repeated application times. No visual symptoms of phytotoxicity were detected. The use of SaviotaN®appearspromising for the control of M. incognitain sustainable agriculture of short-term crops and/or when nematode populationdensities are low and as a supplement to other chemical treatments

Trichoderma secondary metabolites active on plants and fungal pathogens

Beneficial microbes typically produce bioactive molecules that can affect the interactions of plants with their pathogens. Many secondary metabolites may also have antibiotic properties, which enable the producing microbe to inhibit and/or kill other microorganisms i.e. competing for a nutritional niche. Indeed, some of these compounds have been found to play an important role in the biocontrol of plant diseases by various beneficial microbes used world-wide for crop protection and bio-fertilization. In addition to direct toxic activity against plant pathogens, biocontrol-related metabolites may also increase disease resistance by triggering systemic plant defence activity, and/or enhance root and shoot growth. Fungi belonging to the Trichoderma genus are well known producers of secondary metabolites with a direct activity against phytopathogens and compounds that substantially affect the metabolism of the plant. The widescale application of selected metabolites to induce host resistance and/or to promote crop yield may become a reality in the near future and represents a powerful tool for the implementation of IPM strategies

Multiple roles and effects of a novel Trichoderma hydrophobin

Fungi belonging to the genus Trichoderma are among the most active and ecologically successful microbes found in natural environments, as they are able to use a variety of substrates and affect the growth of other microbes and virtually any plant species. We isolated and characterized a novel type II hydrophobin secreted by the biocontrol strain MK1 of Trichoderma longibrachiatum. The corresponding gene (Hytlo1) has a multiple role in the Trichoderma-plant-pathogen three-way interaction, while the purified protein displayed a direct antifungal as well as a MAMP and a plant growth promotion (PGP) activity. Leaf infiltration with the hydrophobin systemically increased resistance to pathogens and activated defence-related responses involving ROS, SOD, oxylipins, phytoalexins and PR-proteins formation or activity. The hydrophobin was found to enhance development of a variety of plants when applied at very low doses. It particularly stimulated root formation and growth, as demonstrated also by transient expression of the encoding gene in tobacco and tomato. Targeted knock-out of Hytlo1 significantly reduced both antagonistic and PGP effect of the WT strain. We conclude that this protein represents a clear example of a molecular factor developed by Trichoderma to establish a mutually beneficial interaction with the colonized plant

Time spent with cats is never wasted: Lessons learned from feline acromegalic cardiomyopathy, a naturally occurring animal model of the human disease

<div><p>Background</p><p>In humans, acromegaly due to a pituitary somatotrophic adenoma is a recognized cause of increased left ventricular (LV) mass. Acromegalic cardiomyopathy is incompletely understood, and represents a major cause of morbidity and mortality. We describe the clinical, echocardiographic and histopathologic features of naturally occurring feline acromegalic cardiomyopathy, an emerging disease among domestic cats.</p><p>Methods</p><p>Cats with confirmed hypersomatotropism (IGF-1>1000ng/ml and pituitary mass; n = 67) were prospectively recruited, as were two control groups: diabetics (IGF-1<800ng/ml; n = 24) and healthy cats without known endocrinopathy or cardiovascular disease (n = 16). Echocardiography was performed in all cases, including after hypersomatotropism treatment where applicable. Additionally, tissue samples from deceased cats with hypersomatotropism, hypertrophic cardiomyopathy and age-matched controls (n = 21 each) were collected and systematically histopathologically reviewed and compared.</p><p>Results</p><p>By echocardiography, cats with hypersomatotropism had a greater maximum LV wall thickness (6.5mm, 4.1–10.1mm) than diabetic (5.9mm, 4.2–9.1mm; Mann Whitney, p<0.001) or control cats (5.2mm, 4.1–6.5mm; Mann Whitney, p<0.001). Left atrial diameter was also greater in cats with hypersomatotropism (16.6mm, 13.0–29.5mm) than in diabetic (15.4mm, 11.2–20.3mm; Mann Whitney, p<0.001) and control cats (14.0mm, 12.6–17.4mm; Mann Whitney, p<0.001). After hypophysectomy and normalization of IGF-1 concentration (n = 20), echocardiographic changes proved mostly reversible. As in humans, histopathology of the feline acromegalic heart was dominated by myocyte hypertrophy with interstitial fibrosis and minimal myofiber disarray.</p><p>Conclusions</p><p>These results demonstrate cats could be considered a naturally occurring model of acromegalic cardiomyopathy, and as such help elucidate mechanisms driving cardiovascular remodeling in this disease.</p></div

<i>Trichoderma</i> Species Problematic to the Commercial Production of <i>Pleurotus</i> in Italy: Characterization, Identification, and Methods of Control

Nine isolates of Trichoderma were obtained from the diverse phases of compost preparation and the production of different commercial varieties of oyster mushrooms Pleurotus spp. with the apparent presence of green mould disease. The isolates were morphologically and genetically characterized. Molecular fingerprinting indicated that the isolates belonged to the species T. pleuroticola and T. harzianum. In order to identify control measures, changes in temperature, pH, and application of fungicides were tested on the present isolates, using known Trichoderma biocontrol strains as a reference. Fungicide effects on the growth of Pleurotus isolates were also assessed. The optimal growth temperatures were 25 °C for Trichoderma isolates and 28 °C for Pleurotus isolates, and Trichoderma always grew faster than Pleurotus. In particular, a reduction of about 30% was recorded for some of the Trichoderma isolates when comparing the colony growth at 25 and 28 °C. Trichoderma isolates developed well within a wide pH range, with the best growth occurring between pH 5 and 7, whereas Pleurotus preferred more alkaline conditions (pH 8 to 9). Prochloraz and metrafenone were found to inhibit Trichoderma growth with different dose responses that did not affect the growth of Pleurotus spp. In particular, metrafenone was the most effective active ingredient that inhibited the majority of the Trichoderma isolates (1–25% growth reduction)